1. Field of the Invention
The present invention relates to a printer in which a platen roller and a recording head are separably combined with each other.
2. Description of the Related Art
As conventionally known printers, there are given known printers in which a recording head and a platen roller, which are held in contact with the recording head, are provided inside a casing, and in which the recording head performs recording on a recording sheet sent out by the platen roller. In the printers of this type, for example, when setting the recording sheet or dealing with jamming, or when maintaining or replacing the recording head, the platen roller, and the like, workability is poor in a case where the recording head and the platen roller are held in contact with each other inside the casing.
In view of this, a printer configuration is desired in which the recording head and the platen roller can be spaced from each other so as to be exposed to an outside of the casing. For this reason, there are known separation-type printers which include a main unit and a detachable unit separably combined with each other, and in which a recording head is provided to one of the units and a platen roller is provided to the other of the units.
According to the separation-type printers, the recording head and the platen roller can be combined with each other under an appropriate press-contact state when the detachable unit is combined with the main unit, and the recording head and the platen roller can be spaced from each other to be exposed to the outside when the detachable unit is separated from the main unit. Therefore, the separation-type printers described above are easy to use and are excellent in workability when performing the above-mentioned various operations.
Incidentally, in the case of the separation-type printers, it is important to reliably combine the main unit and the detachable unit together with less looseness, or to perform smooth attachment/detachment operations. Thus, as printers meeting such a demand, there is known a printer adopting an arm-type locking method (see Japanese Patent Application Laid-open No. 2000-118060).
The printer includes a body frame provided with a thermal head, and a cover frame provided with a platen roller, and has a configuration in which the cover frame is separably combined with the body frame through opening/closing operation of the cover frame.
A hook-shaped lock lever is pivotably attached to the cover frame, the hook-shaped lock lever having a tip end serving as an engagement portion. Meanwhile, the body frame is provided with a lock pin on which the engagement portion of the lock lever is engaged.
According to the printer thus configured, when the lock lever is pivoted so that the engagement portion is engaged onto the lock pin, it is possible to reliably combine the body frame and the cover frame with each other, and to bring the thermal head and the platen roller into press-contact with each other. Further, when the lock lever is pivoted in an opposite direction so that the engagement portion is disengaged from the lock pin, it is possible to separate the body frame and the cover frame from each other.
In this way, with use of the lock lever, it is possible to reliably combine the body frame and the cover frame with each other, and to perform smooth attachment/detachment operation of the cover frame.
However, in the above-mentioned printer adopting the conventional arm-type locking method, in order to engage the engagement portion onto the lock pin, the lock lever needs to be provided to the cover frame while protruding to the body frame side. Therefore, the lock lever projects outward further from the cover frame in a direction in which the body frame and the cover frame are combined with each other, and hence miniaturization of the entire printer is hindered.
Further, the lock lever is attached onto a side surface of the cover frame, and is arranged on any one of the inside and the outside of a wall of the body frame when the cover frame and the body frame are combined with each other. Accordingly, a size in a width direction of the printer (in a width direction of the platen roller) is increased by at least a thickness of the lock lever. Even in this respect, the miniaturization is further hindered.
Still further, the lock lever protrudes outward further from the cover frame, and hence fingertips easily touch the lock lever as a protrusion, which is susceptible to improvement in terms of safety.